Oil gas process and apparatus



Dec. 22, 1953 L, BOR 2,663,625

' OIL GAS PROCESS AND APPARATUS Filed Nov. 22, 1948 2 Sheets-Sheet l 5 CHECKERS CHECKERS INVENTOR. Paallfiarw,

Dec. 22, 1953 P. L. BORN on. GAS PROCESS AND APPARATUS 2 Sheets-Sheet 2 Filed Nov. 22, 1948 I f I/ 1/111 I/ l ,X I I C I INVENTOR. f L150 rm, BY

Patented Dec. 22, 1953 UNITED STATES PATENT OFFICE 2,663,625 OIL GAS PROCESS AND APPARATUS Paul L. Born, Wilmette, Ill.,

assignor to The Gas Machinery Company, Cleveland, Ohio, a corporation of Ohio Application November 22, 1948, Serial No. 61,472

9 Claims.

ber and variety of forms of apparatus, and particular methods of operation, bon oils or fuel oils to make types of fuel gas.

In spite of the current relatively high cost of fuel oil, the use of this material as the source of hydrocarbons for producing a high B. t. u. commercial fuel gas offers several attractive features. An oil gas process is particularly advantageous for stand-by facilities to be used intermittently to augment the supply of natural gas to a municipal gas distribution system.

The terminology, oil gas as used'herein and in the appended claims, refers to fuel gas formed by the cracking and destructive distillation of fuel oils, and excludes the presence of any substantial content therein of gases formed from carbon or steam, or any reaction therebetween.

An important object of the invention is the provision of an efficient cyclic process of making an oil gas which is interchangeable with 1000 B. t. u. natural gas, which process can be effectively carried out in existing carburetted water gas sets with only minor modification of such existing equipment.

Since existing sets of this type comprise a substantial investment and the building of new equipment is a costly undertaking, it is an important part of my invention to be able to inexpensively convert the existing equipment to produce a gas which is interchangeable with natural gas and adaptable for use in existing consumer appliances. A better understanding of the accomplishment of this object will be gained if the limitations of existing carburetted water gas sets are understood.

About sixty years ago a process for making commercial fuel gas was brought out called the Carburetted Water Gas process. Briefly, it consisted of blasting a bed of hot carbon with air, forming producer gas, and burning the producer gas evolved with more air to heat the refractory brick in subsequent chambers. When the refractory filled chambers were heated to about 1400 F., the blasting was discontinued and steam was passed over the hot bed of carbon, forming for using hydrocarvarious grades and that could be blown over 2 Water Gas. The Water Gas" then passed over the hot refractories in the subsequent chambers, being joined in the first refractory chamber by a stream of liquid hydrocarbon, which gasified on the hot refractories and broke up as the temperature increased into simpler and more complex hydrocarbons.

gas to form carburetted Water Gas, while the tar condenses out as liquid when the permanent gases are cooled.

The capacity of a standard water gas set as described above was limited by the amount of air the hot fuel bed of the generator per minute, because this controls the heat generated, and thereby controls the quangas that could be made later. The blasting process was exothermic, and the gas making process was endothermic. axiomatic that the heat ing portion of the cycle heat used in the gas making portion of the cycle.

Standard carburetted Water gas sets were customarily designed so that the producer gas made in the generator or first chamber could be completely burned and the resultant heat stored in the refractories of the second and third chambers. The upper limit to the rate of blasting is the point where fuel would be blown out of the fuel bed.

Years of operating experience in the production of 530-565 B. t. u. carburetted water gas resulted in a balance in design of the component For example, the air blasting required, after a run, to reheat the fuel bed produced just double the refractory brick placed in the carburettor. Three shells of the largest sets built were approximately twelve feet in external diameter, nine feet in internal diameter. The generator and carburettor were about twenty feet high, and the superheater about thirty .feet high. Carburetted water gas sets thus proportioned would make from three million to five tories twice as much as before. "Furthermore,

million cubic feet of gas per day, dependent upon the heat value and specific gravity of the gas desired.

The heating value of carburetted water gas in the manufactured gas industry ranged from about 530-565 B. t. u. per cubic foot. A typical 540 B. t. u. gas consisted of 81.5% of water gas having a heating value of 300 B. t. u. per cubic foot, and 18.5 of oil gas having heating value in the order of 1600 B. t. u. per cubic foot. The specific gravity of the finished gas ranged from 0.60 to 0.70. A typical analysis of 540 B. t. u. 'carburetted water gas is as follows:

CO2 6.0 Ilium 9.8 02 0.0 CO 30.0 Hz 40.0 CH4 10.0 .Nz 4.2

l B.t.u 540 *Sp. gr 0.61

This heat value was controlled generally by the "fact that carburetted water gas sets wereused to inake' peak loadand emergencysupplies of gas in conjunction with the :base load coal gas 'of approximately 550 ':B. t; u.1per cubic :foot.

' About twentyyears a'goincreasing amounts of natural gas fromthe'Southwest began'to be available for general use, and began to supersede the -'-use of coalgas'as abas'e' load: gas. This natural ''gas had aheativalue ofi-more than 1000 B. t. u. per cubic foot and a'specifiegravityoi. about 0.65. It therefore became necessary :to-producetlOOO "B. t. u; gas on the peak load and emergency units. The gas utilities were faced with the problem of adapting their :carburetted .water'gas sets. (designed'ior'530- 5'65 B. t. u: production) to produce 1000 B. t. u. gas,'and such gas should be inter- -changeable with naturar'gas forconsumersi'appliances.

When a 500 B. t.u.'ca'rburetted water. gas set is operated according to previous practice to -make 1000 13. tgu. carburettedwater: gas, i relationship betwe'eniblower capacity, generator, carburettor and superheater size; 1 and checker brick is'disturbed. iIt: in'volvedradicali changes inoperation.

in the final gas had to be decreased tomaintain a 1000 B; t. u. percubiefoot output. That is, the water gas contenthad to be reduced, for example, iromabout 81.5 %i;at:300"B. t; u. to about.46% and-thepoil gas content had :to be raised from about 18.5% at1600B. t. u; .to abouti54=%. affected the'thermalibalance of the set. vThe fuel bedwas cooledo'nly-halfas much, and the refrache temperatureiandztime' of contact relationship in the set forcilcracking was radically disturbed. in addition, the carbon monoxide oi the finished :gas adversely affected the interchangeability of the 'gas produced. .Carbon monoxide does ,not have the same B. t. unspecific gravity relationship 'that exists:inhydrocarbon-gases.' In effect; the carbon monoxide constituent-increases the specific gravity of thefinished gas, and in considering inter changeabilitywith natural gas, carbon monoxide reduces the burner input (thru laws effectingflow thru orifices) andproduces aleaner primary air'mixture in-burners', which results in an increasedrate-of flame propagation at the burner *head. "Furthencarbon monoxide, is a much faster *burninggas than theconstituents oitnatural gas.

the efiicient I First,l.the Water gas constituent To recapitulate, the gas was not a good sub-' stitute for natural gas, and had the following defects:

(1) It had a higher specific gravity, which decreased the burner input on burners properly adjusted for natural gas. Since the primary air iniection on these burners would remain the same as before, the ignition velocity of the air-gas mixture was increased due to the higher aeration.

(2) The chemical composition of this gas gave "it an inherently higher ignition velocity, which,

ing characteristics on below. The space above the combined with the speedup of ignition velocity mentioned in paragraph (1) gave very poor burnburners adjusted for natural gas.

Two other matters were deemed undesirable in carburetted water gas operations:

1. The presence of carbon monoxide in the gas causes it to be toxic. Elimination of carbon monoxide was deemed to be beneficial from the health standpoint.

2. A well trained personnel required to operate a iuel'bed in a carburetted water gas set was very difficult and expensive to maintain on the small amount of operation found necessary-for peak load and emergency-service.

It willbe seen, therefore, that the need, when producing 1000 B. t. u. gas, is for a method which uses efficiently the equipment built into the 550 B. t. u. carburetted water gasset', which produces aminimum of'carbon monoxide, and which requires a minimum of changes in the equipment itself. Good interchangeability with natural gas must also be attained.

I have discovered the manner in which the above can be accomplished. Fundamentally, this consistsoi eliminating the'solid fuel bed in the generator-and installing a burner oil spray for heating the set in its place. Carbon monoxide is ordinarily produced by the reaction of steam on incandescent carbon. Since there is no fuel bed, no carbon monoxide can now be madein the generator. I have discovered that this spray must be installed in a horizontal position, just above the grates which are loosely covered with'firebrick, for protecting the iron from heat, so that the finely divided oil spray will spread uniformly over the area through which the blast comes from grate audits protective checkers in the generator then constitutes the opencombustion chamber and that combustion chamber is free of checkers or bricks. In order to obtain the advantages of the horizontal spray at the lower portion of the combustion chamber it is necessary to provide means'for safe ignition. This is'doneby using an ignition pile of refractory which will not be cooled by the inset. Steam input-is coming air blast. This ignition pile in combination with the horizontal spray is a further part of my invention. 1' find that in this way I can utilize'the full capacity of the blower, and maintain a heat baiance that will not necessitate changes in the-original design pro'portions of the such that carbon deposited in the set does not react with steam during the make period. It will be noticed that I thus utilize the existing generator and carburetor in series as originally designed, and the output of these without any changes.

two units in series with the superheater, also No additional 'cheekerbrick is: required in the generator to maintain this balance.

.Another important object of the present invention is the provision: of a cyclic process for making oil: gas with; substantially no J attendant filled wherein during the gas making phase steam is passed upwardly through the generator and its open combustion chamber and absorbs heat from formation of water gas and residual carbon, in which cyclic process there is a heating phase wherein fuel oil is completely burned in an open combustion chamber of a generator with an excess of air and the products of combustion and excess air are used uniformly to heat refractory checkers in carburetor and superheater chambers, and there is a gas making phase in which fuel oil is sprayed onto the heated checkers in the carburetor and steam is used to displace and carry ofi the oil gas formed in the carburetor and superheater without itself reacting with carbon that may be uniformly deposited in the checkers or otherwise being decomposed or altered to any material extent.

Another important object of the present invention is the provision of a cyclic oil gas process wherein during the heating phase, fuel oil is burned in the generator in an open combustion chamber free of refractory or checker work, except for the lining of the walls and bottom, and an excess of combustion air is used which serves completely to burn the fuel oil in the combustion chamber and also to temper or control the temperature of the refractory walls of the combustion chamber so as to prevent overheating thereof while withdrawing heat from the combustion chamber and uniformly transmitting such heat to the checker work of a carburetor and superheater connected therewith, and in addition the excess air burns off all carbon deposited in the checker work of the carburetor and superheater.

Another important object of the invention is the provision of a cyclic process of making oil gas in an apparatus comprising a generator having an open combustion chamber having a fuel oil spray located in the lower portion thereof and connected at the upper portion thereof in series with a checker-filled carburetor and a checkerfilled superheater, and wherein the fuel spray in the combustion chamber may, if necessary, be used during the gas making phase as a means of cooling the refractory lining on the combustion chamber should it tend to become overheated.

Another important object of the invention is the provision of a cyclic oil gas process and apparatus therefor, wherein during the heating phase, a spray of fuel oil is ignited and burned in a generator in admixture with excess air adjacent to the bottom of a refractory lined open combustion chamber free of checkers, thereby allowing for complete combustion of fuel oil as the combustion gases rise through the chamber with the refractory lining extracting heat therefrom before the combustion gases leave the top of the combustion chamber and pass in series through checker carburetor and superheater units, and

the refractory lining thereof which is utilized in 'the thermal decomposition of make oil introduced into the top of the carburetor unit, thereby making full use of the refractory lining of the open combustion chamber as a heat extracting sink a during the heating phase and as a source of heat during the gas making phase.

Another object of the invention is the provision of a cyclic process and apparatus for making oil gas wherein a spray of oil is completely burned with an excess of air in a combustion chamber free of checkers or refractories which is in turn connected with a carburetor having approxiher but an operative portion'of which is filled with checker work or refractories.

Still another important object of the present invention is the provision of a cyclic process and apparatus for making oil gas wherein during the heating phase a spray of oil is delivered into the lower portion of an open combustion chamber of a generator so as to form a relatively thin horizontal cloud of oil spray above the bottom of the chamber, and an excess of combustion air is introduced underneath the oil spray cloud so as to sweep across the bottom of the generator and absorb heat therefrom before it rises upwardly through the combustion chamber.

Still another important object of the invention is the provision of an apparatus or set for making oil gas by a cyclic process wherein the fuel oil for heating the set is burned in an open combustion chamber of a generator with the fuel oil being introduced in the lower portion of the charm her over a relatively thin body of open checker work through which the combustion air riseshand wherein there is an upstanding body or pile of refractory disposed on said open checker work and closed to the passage of air therethrough, such refractory body or .pile being heated to incandescence during the. heating phase and serving positively to re-ignite the oil at the commencement of each heating phase.

Certain other objects of the invention will, in part, be obvious and will in part appear hereinafter.

For a more complete understanding of the nature and scope of my invention reference may now be had to the following detailed description of three specific embodiments thereof taken in connection with the accompanying drawings, wherein:

Figure 1 is a diagrammatic, vertical sectional view of an apparatus for carrying out my improved cyclic oil gas process;

Fig. 2 is a diagrammatic sectional view taken on line 2--2 of Figure 1;

Figure 3 is a diagrammatic, vertical sectional view of a three-shell water gas set converted in such manner than my improved cyclic water gas process may be carried out therein; and

Figure 4 is a diagrammatic, vertical sectional view of a single shell Williamson carbureted blue gas apparatus modified and adapted for carrying out my cyclic oil gas process therein.

Referring to Figures 1 and 2 of the drawings. the reference numeral 5 designates a generator having a combustion chamber 5a, the side walls and :bottom of which are lined with refractory brick 6. The bottom of the generator 5 is provided with a combined air and steam inlet 1 which discharges tangentially over the bottom of the combustion chamber 5a as shown in Figure 2. The introduction ofair through the inlet l is controlled by means of a valve 8 while the introduction of steam is controlled by means of a valve 9 in the steam connection II.

The top of the generator 5 is provided with a dome I2 having an outlet l3 connected by a flue connection M to the inlet I5 in the dome l6 of a carburetor H.

The combustion chamber 5a is provided wit an oil spray or burner III in the lower portion thereof at a level above the air and steam inlet connection 1. The oil spray I8 is so arranged as to deliver an atomized spray of oil into the lower part of the combustion chamber so as to form a relatively fiat or fan shaped. cloud Of'Oil ex- .mately the same cubage as the combustion chamtending across the. combustion chamber.

i1 is 'As a precautionary i measure xfonz. preventin overheating of the r'efractory iliningzirr .theidome l2; an 'oil' spray-19 is' de'sirably provided. =;By introducing a spray of oil ati' l'9:during thergasmaki'ng" cycle theresultin'g) spray :wm: serve =to cool the refractory-lining: in' the dome l2 An oil spray20 is'provided inthe top of the dome IS of the carburetor Wafer-introducing.oil

into the carburetoroverrthetop of the. checkers therein during th'e'gas makingphase of the cycle of 7 operation.

The'bottom of the carburetor I1 is open at the 1 space 2| 'below the checkersandthisspace communicates with acorrespondingspace 22under- 'neath' the checkers in a superheater 23. 'The top of thes'uperheaterfl' is providedwith a-dome having an outlet connection'25. The top of the outlet connection 25 isclosed by-a-stack valve or cover Which may be openedvand-closed 'by means of themechanismi'l. A fuel gasofftake.

pipe 28 exte'ndsfatiright angles from the outlet connection'25 and' discharges into awash box 30 through the connection ill-the Outlet end of which extends "well down into w the wash. box 30 and is normally submergedunder thewater therein. A water spray. 32'may be'providedinthe-offtake connection 28 which serves to spray a. stream of water over-the sides of thezofftake connection 28 and the connection l-thereby'preventingformation of carbon on thesemetalpipes, and also to assist cooling of -th'e. exit :gas. The wash box 30 may be provided with the usual seal pot.

33 and it is also provided withwa gas outlet connection 34 wherethrough the fuel gas may bedischarged to a'holder' or to -.a=distributionsystem,

One of"severalssuitable"constructions for the generator Sycarburetor H and -superheater= 23 is an outer shell of steel adjacent to which is a three inch layer ofinsulation shielding .the'steel from a nineinch'lining ofrefractory bricker An 1 operative portion of=boththe= carburetor and superheater. is "filled" with: checkerwork. The

checker work in the carburetor l'L-and in-the superheater 23 may take anyone ofjthe. conventional'forms used for 'this purpose.

In operation; oilsgas'is made inrthe apparatus .shown in Figures'l and '2 as follows: .The heating phase of thexcycl'icprocess is initiated by intro- 'ducing'air throughithe' open --valve '8' into the "bottom of ithe generatoriand its: combustion chamber and'oil into'the fuelroil spray I8, this oil being'ignited by5suitable-ignition means (not tsh'own) a The air should bezintroduced intc -the combustion chamber atiairate. at' least sufficient I completelyto burn all oftheh'eating oil asvwell as all of-the carbon deposited onthe checkers in carburetor l1 andsuperheater 23. ".The proper rate of air-introductionmay readily be obtained 1 by mtroducingsufiicient air so that the new gas from stack 23 will contain approximately 10% air as shown by a CO-zanalysis: As the incoming air enters thebase of the generator 5- and its combustion chamber 5a it follows :a turbulent path 'over the bottom refractory, as indicated by the arrows 35 in-Figure2; and absorbsheatfrom these heated refractories .before risingvertically through the oil spray cloud 36. as indicated by the arrows 31 in Figure l. .The spray .cl'oud 36 isburnd with complete combustionias the gases rise thrOughWhe combustion: chamber Sa-and by the' time these gases reach'the-dome i2 the:com- 'bu'stio'n is c'om'plete andthe: gases flowing :over into the carburetor I1 -"through'thetconnection ll are'inthe Iormofi let e combustion: gases p'f -flrkinotizconsumed.

admixed'wlthtlie exe The-products; ot'combustion fiow downwardly through: the carburetor I'lthereby heating the .zcheckers therein with complete uniformity and r thence-upwardly through; the superheater 23 'heatingthe checkers therein also with complete 1miformity. During, the heating phase of the process the stack valve 26 is open and theprodnets of combustion-together with the excess air are: discharged therethrough to the stack.

...Typically. the heating period may take. ap-

- proximately 2.2 minutes, or about% -of -the cycle, and the checkers in the carburetor H and in the superheater-ZS may be uniformly heated --to temperatures of about1450 F. and 1400 F.

respectively.

The excess air not onlyv insures complete combustion of the fuel oil in the combustion-chamber 1 5a but also servesas a heat absorbing medium so as totemper the -products of combustion, and,

together with the heat absorbed .during the gas making period, prevents the overheating of-the --refractory lining: of the combustionchamber.

-- Furthermore, excess air servescompletely to burn out and-remove deposits of carbon in the checkers formed during each gas making phase before'anothergas making phase is initiated. Inthis oif-the airsupply, and the valve!) is opened: ad-

- manner, the production of water gas is substantially entirely avoided.

After the heating phase iscomplete, the stack valve 26 is closed, the; valve 8 is closed shutting mitting steamintothe-bottom of-the combustion chamber 5a. The oil spray 20 isturned on, while the oil :spray l8 inthe combustionchamber 5a may or mayinot be turned-on depending upon the particular conditions under which the apparatus is being -operated.- The steam becomes formed. andoloes not itself enter intothe formation of the gas to. any appreciable extent. .The fueloil sprayed into the top of the carbure- .,tor l1 throughspray 20 is-usually arelatively light grade fuel oil, such,.for example, as diesel oil or. #2 furnace oil. If desired, tar or a relativelyheavygrade of fuel oil is introduced into the oil-burner. l8land burned in. the combustion ..chamber 5a. As mentioned, this latter tar or oil spray may bemaintained during the gasmaking phase in. order tov absorb part of the. heat. and

thereby .c001.,the highly .heated refractory. lining of the combustion chamber. 7 The oil injected into the .combustion chamber in .theHmake phase is .'.cracked thereinto form-hydrocarbon gases which pass with the steam into the top-of the carburetor 11. .The. large. amounts of heat stored inthe refractory lining of the combustion chamber and the absence of checker work make it practical so to use heavy fuel oil ,and even tar in the make phase.

If during the courseof operation the refractory lining of the combustion chamber Sci-tends to overheat; oil-may be sprayed intothecombus- ..tion chamber during one or more gas making phase through eitherithe oil spray I8 or. the oil spray 1.9, .onbothii; necessary... In this;connec- 'tion, the spray I8 serves primarily to protect the lower portion of the lining while spray l9 serves to protect the lining in the dome I 2.

The fuel gas leaving the top of the superheater 23 passes through the connection 28 down through the connection 34 into the wash box 30 and leaves the apparatus through the discharge connection or elbow at. The steam is partially condensed in the wash box and the oil gas leaving the apparatus may have the following typical composition:

Per cent by volume CO2 1.6 Unsaturated (illuminants) 21.2 C2 0.5 CO 1.2 H2 28.4 CH4 42.9 C2Hs 2.3 Na a 1.9 B t. u n: eve Tart. Specific gravity 0.66 When there is more blow purge, the composition may change, as follows:

Per cent by volume CO2 3.2 Unsaturated (illuminants) 23.4 2 1.0 CO a 2.2 Hz 17.0 CH4 32.3 Cal-Is 5.4 N2 a a 15.5

t. u 990/cu.ft. Specific gravity 0.85

After the checkers in the carburetor I T! and superheater 23 have become cooled, thegas making phase is terminated, the apparatus is purged with air With the main air blast valve open to thereby clear the set of oil gas and then the heating phase is re-initiated. With the operating conditions during the heating phase being those mentioned above, the gas making phase may takeapproximately 1.8 minutes, or about 45% of the cycle.

It will be understood that the typical operating data given above in connection with the apparatus shown in Figures 1 and 2 are for purpose of illustration and a more complete understanding of the nature and scope of the invention, and are not to be interpretedin a limiting sense.

In connection with the operation of the apparatus shown in Figures 1 and 2, it will be noted that during the heating phase, no combustion of fuel oil occurs within the carburetor or superheater. This has been found to be a very important feature of the invention since it permits, and in fact insures that, the checker work in the carburetor I! and also the superheater 23 will be uniformly heated by heat absorption from the combustion gases leaving the generator or combustion chamber 5a without placing a restriction on the amount or rate of heat input to these structures. As long as the checkerwork is thus uni formly heated, the tendency for carbon to deposit during the gas making phase is lessened and such deposits as are formed will be uniform. Thus, a serious difficulty that is ordinarily encountered in operating oil gas sets is overcome. That is, when combustion occurs-in part in the'checkerwork, it becomes unevenly heated and carbon deposits will be heavier in the hotter areas; Then, when the carbon is burned off these heavier carhon deposits cause local hot spots and this situadownwardly through the 10 tion normally becomes increasingly aggravated as the process continues, Y I As indicated above, one advantageous feature of the present invention is the ability conveniently and economically to adapt or convert existing carburetted water gas generators from solidfuelto liquid fuel so as to take advantage of my improved cyclic process. Referring to Figure 3 of the drawings there is shown therein a standard three-shell water gas set modified for operation in accordance with my present invention. Three courses of checkers 4|] are placed over the regular grate 4| to protect the same and an oil burner 32 is installed just above the checkers 40 in the lower portion of the combustion chamber 43a of the generator 43. In order to provide for re-ignition of the oil at the commencement of each heating phase, a pile or stack of refractory 39 is placed on the checker-work 40. The refractory pieces forming the stack 39 rest on a closed base so that it will not, be cooled by air or steam passing therethrough. The regular air inlet 44 into the bottom of the generator 43 is provided with the usual valve 45 and the steam inlet connection 46 is provided with the usual valve 41. The usual connection between the bottom of the generator 43 and the upper portion of the checkers in the carburetor off. The fuel oil spray buretor 48 is retained.

Since the refractory lining in existing installations may be rather limited in respect to the temperatures which they may safely withstand, it may be desirable to provide an auxiliary oil spray 56 adjacent to the top of the combustion chamber 43a of the generator 43 whereby fuel oil may be introduced during the gas making phase so as to cool the upper portion of the generator.

vIt will be seen that the apparatus shown in Figure 3 may be operated generally in the same manner as the apparatus described above and shown in Figures 1 and 2. That is, there is a heating phase in which air is introduced into the bottom of the generator 43 and flows upwardly through the protective brick work 40 to burn the spray or cloud of oil admitted through the oil burner 42 in the combustion chamber 43a above the protective brickwork 40. An excess of air is used and the products of combustion together with the unconsumed air pass over to the carburetor 48, downwardly therethrough, and then upwardly through the superheater 5! thereby. heating the checkers in both units. The combustion gases leave the apparatus through the open stack valve 52. After the heating periodv has been complete, the stack valve 52 is closed and the air supply valve 45 is also shut off an the steam valve 4'! is opened. the oil spray is established and the steam flows upwardly through the generator 43 becoming superheated as it draws bottom thereof and then passes over to and I carburetor 48 and then upwardly through the superheater 5 I. The steam serves as a carrier or displacer for the oil gas 50 into the top of the cargenerated in the carburetor and superheater- Oil gas leaves the superheater from the top through the conection 53 and discharges into the usual wash box 54 from which it leaves through the elbow connection 55. If desired, the oil spray 42 may be continued during the gas making phase of the cycle in order together with the excess air supplied during the heating phase, to control the temperature of the refractory lining of 48 is removed or blocked heat from the walls and thermal capacity of the setis doubled, the labor problem is reduced, and carbon monoxide in the resulting gas is largely eliminated. This gas can be substituted nearly 100%for natural gas. A typical gas analysis follows:

CO2- c 2.2 Ill 23.6 02 0.8 CO 1.4 Hz 22.2 CH4 p--- 42.0 CzHe 2.1 N2 5.7

B. t 11 I .1023 Sp. gr .0373 Refractory temperature F 1600 When better grades of oil can obtained for feed stock, better interchangeability" can be :obtained, due to further reductioni'in' carboni dioxide, carbon monoxide and nitrogen;

This method of converting a'standard water gas processto an oil fired oil gas process is generally distinguished as follows:

1.-: Low investment cost of conversion.

2. improvement of gas "burning characteristics; due to the eliminationof carbonmonoxide.

3. 'I'he-' same relative costs-of manufacture per therm.

4. Reduction of labor problem;

'In' Figuredofthe drawings there is shown a Williamson single shell carbureted blue gas apparatus converted in such manner as to operaterinuaccordance with the present invention. Protectivecheckers 60 areinstalled above the grates over the protective checkers BO-in'the lower por tion of the combustion chamber 58 of the generator 51.? An ignition pile 60a" having a closed bottom 0 and'resting Onthe protective-checkers 60, in a manner and location: similar tothe pile 39' of Figure 3,'is employed for automatic'ignition purposes. Inoperation; in the. heating phase pri mary air is introduced through the airsupply connection 63' through the open valve and flows upwardly through the protective checkers 60 to burnthe oil spray introduced 'by the burner. 62

inthe combustionchamberiih The products of combustion flow upwardly through the combustion chamber. 58 of thegenerator heating the refractory walls thereof and thence. pass up.- wardlyv throughthe outside flue pipe or connection 65 leadin to a vertical connection 66. leading into the 'top of the carburetor chamber 61. An excess of air is passed upwardly through the generator and the products of;combustion to.- gether'withthe unconsumed air serve uniformly to heat-the checkers in the carburetor chamber 51 as well-as the checkers ingth'e superheater. chamber or section 68'. A'portion of theexcess air may be introduced-through what originally was asecondary air'valvej59, so as to give a greater cooling effect to the refractory lined flue 6i and anwoil burner 62 is installed 'just' 65. During the heating period the stack valve To is opened allowingthe :gasesto pass upwardly through the stack '1 l.

After the heating phase is complete, the stack valve 10 is closed,rthe air supply valve 64 is closed and the steam valve 12 leading into the bottom of the generator 51 is opened. The steam sweeps upwardly through the generator 5'! and its combustion chamber. 58 absorbing heat therefrom and-enters the carburetor .61 through the top thereof. At the same time the oil spray i3 is opened which serves to spray fuel oil on top of the checkers inthe carburetor 61. The steam sweeps'the' oil gasesformed from the fuel oil downwardly through the carburetor 6T, upwardly through the supcrheater 88 andthence' out throughthe 'gas'ofitake "14. The gas oiftake M dischargesinto-the usual wash'box I5 and leaves the same through the outlet connection'lfi.

In order to protect the refractory'linin in the top of the generator, it is "desirableto provide an auxiliary oil spray--11 through which oil may, when necessary, be sprayed during the gas making phase.

It will be noted that'the cubage'of the carburetors in the apparatus shown'in Figures 3 and-'4, exclusive-of the checkers therein, is approximately equal to the 'cubage of the respective generators. Even though the apparatus is operated-in a cyclic'manner and'steam is used in the gas making 'phaseto carry out and displace the fuel gas generated; substantially no other gas is formed during theoperationexcept for the small amount of blow-purge gas. Such carbon as is uniformly deposited in-the checkers during the gas making vphase is rapidly and completely burned .off duringsthe initial portion of the following heat phase without production of local-hot spots. It will thus be apparent that the operation of the apparatus shown. in Figures 3 and 4 is generally the same as that described in detail above for .the. apparatus shown in Figures-1 and 2. V

The protective refractory checkers 40 -(Figure 3) and the protective refractory checkers 50 (Figure 4) become highly heated during'operation of the respective converted'carbureted water gas generators thereby permitting use of heavier oil and tarfor firing and also permitting utilization of'ig'nition piles-such as.39 (Figure 3) or SM (Figure 4) Automatic control equipment of known type may be used to control'the operation of the cyclic process.

It'will be understood that the cyclic process of the present invention may ,beadapted to other types of gas making apparatus and that the specifi'c embodiments described above are given by way of. illustrationwiththe-understanding that the invention may be practiced in other embodiments.

Having fully described my invention, what is claimed as new is:

l.-In a standard'three chamber carburetted water gas set which has a generator with a combustion chamber and a carburetor, and a superheater; with the outlet ofxthe combustion chamber connecting-with the inlet of the carburetor chamber and the outlet of-the carburetor cham ber connecting with chamber andwith said last two chambers each having an operative portion filled with checkers, and a grate in the lowerportion of said generator beneath isaidcombustion chamber and air and steam inlets in the base of the generator beneath the inlet of the superheater aaeaoec cover of checkers on the grate at the bottom portion of the combustion chamber to protect the grate, a fuel oil spray adjacent the inner vertical wall in the lower portion of the combustion chamber above the protective checkers adapted to discharge a horizontal spray across the lower portion of the combustion chamber in place of using solid fuel and thereby to permit an open combustion chamber, and refractory ignition means located in said combustion chamber inwardly from the wall and above said protective checkers in line with the fuel oil spray, whereby the set may produce gas having a calorific value and specific gravity making it interchangeable with natural gas of approximately 1000 B. t. u. per cubic foot.

2. The improvement set forth in claim 1 wherev in the ignition means comprises a refractory pile disposed directly on the protective checkers and provided with a closed base so that it will not be cooled by the upward passage of air or steam through the pile.

3. The improvement set forth in claim 1 wherein the fuel oil spray substituted for solid fuel provides a relatively thin fan-shaped cloud of oil which is sprayed across the combustion chamber in a horizontal plane above the protective checkers.

4. The cyclic process of making oil gas which is interchangeable with natural gas having approximately 1000 B. t. u. per cubic foot with substantially no attendant formation of water gas in a standard three-chamber water gas set which has a refractory lined generator having a grate .1

and a combustion chamber formed above the grate with the combustion chamber and carburettor chamber being interconnected with the outlet of the combustion chamber connecting with the inlet of the carburettor chamber and ing a calorific value of from 530 to 565 B. t. u.

per cubic foot, said process comprising forming a relatively thin horizontal spray of fuel oil above the grate in the lower portion of the open combustion chamber which is free of checkers, introducing an excess of combustion air into the bottom of said generator to fiow upwardly through said grate into the combustion chamber cross current to said oil spray to provide an intimate intermixing and combustible mixture of the oil and air above said grate at the bottom portion of said combustion chamber, completely burning said oil spray with said excess combustion air in said combustion chamber and heating an ignition pile in the combustion chamber to incandescence so that it will serve positively to re-ignite the oil at the commencement of the next heating, phase, passing the products of combustion together with unconsumed excess air through said carburettor and then through said superheater, thereby uniformly heating the checkers therein to oil gas making temperatures in the neighborhood of 1400" F. to 1800 F. and at the same time burning off any deposits of car bon that may have been deposited on the checkair and fuel oil into the combustion chamber after said checkers have been suiiiciently heated for oil gas making, thereby completing the heating phase of said cyclic process, and then commencing the gas making phase by introducing steam into the bottom of said generator beneath the grate and thence through the combustion chamber and spraying oil into the carburettor at a place adjacent the inlet thereto, said steam absorbing heat from the walls of said chamber as it passes therethrough and being introduced in sufficient volume to sweep up through said combustion chamber and thence through said carburettor and superheater so as to displace and carry away the oil gas formed and fixed in said carburettor and superheater, respectively, without itself being decomposed to any substantial degree, discontinuing said steam introduction and said spray of oil into said carburetor after said checkers have become cooled to a predetermined temperature, and "purging the apparatus of oil gas by an air blast preparatory to initiating another heating phase, thereby completing one cycle of said cyclic process.

5. The process of claim 4 wherein a relatively heavy grade of fuel oil is sprayed into said combustion chamber and a relatively light grade of fuel oil is sprayed into said carburettor during the gas making phase.

6. Apparatus for making oil gas, comprising a refractory lined, vertical generator having an open combustion chamber substantially free of checkers, a carburetor and a superheater each having an operative portion filled with checker bricks and interconnected in series relation whereby exit gases leaving said combustion chamber enter the inlet of said carburetor and exit gases leaving said carburetor enter the inlet of said superheater, said combustion chamber being provided with oil burner means in the lower portion thereof but at a level substantially above the base of said generator, air and steam inlets discharging into the base of said generator beneath the oil burner means whereby air and steam introduced therethrough flow over and in contact with the base of said generator prior to rising upwardly therethrough, and ignition means located in said combustion chamber inwardly from the wall and disposed at a horizontal level corresponding to that of the oil burner means.

7. In apparatus for making oil gas which has a generator with a combustion chamber and a carburetor and a superheater, with the outlet of the combustion chamber connecting with the inlet of the carburetor chamber and the outlet of the carburetor chamber connecting with the inlet of the superheater chamber and with said last two chambers each having an operative portion filled with checkers, and a grate in the lower portion of the generator beneath said combustion chamber but substantially above the base of the generator and air and steam inlets in the base of the generator beneath the grate, the improvement which comprises checkers on the grate only to a depth sufficient to protect the grate with said combustion chamber being entirely open thereabove, and a fuel oil spray having a horizontal delivery adjacent the innervertical wall of the combustion chamber above the protective checkers at the bottom of the combustion chamber for discharging a horizontal spray of oil across the bottom portion of the combustion chamber in place of using solid fuel, said checkers on the grate being so disposed on said grate as to distribute evenly and cross-wise of the horizontal spray'ofoflxthe incomingair from the. base a of the :generatorfor vproviding an intimate inter;-;- mixing -andcombustible-mixture of excess air. and OiLatthEIbOttOm or .the open combustion :cham-v ber of the generator so: thattheentire opencombustionwchamberris .cused .'in::producing.- complete combustion; of the oil before the products "of com-i bustion i and excess .airi. leave the combustion chamber :to, cross overtoithe. carburetorchamber; 8. The; apparatus of claim '7, together. with a fuel oil sprayadjacent the inner wallt'of the com-.

bustionr chamber-inf thesigeneratorgadjacent the top :of :saidrlchambenzthe :fuel 1 oil spray. at the bottom ofxthe :combustion: chamberabove .the grate and :the fueloil spray at the top'oithe com-A bustion chamberbeing adapted .to be used, during the gas-.making phase -oft the apparatus; for ire-.

ducinghundesiredsexcessive temperatures of the I wholelengthcf'the-refractoryzwalls oi the combustionchamber 9.: In:the.- process .of :making' oil; gas. which is interchangeable with natural-gas having approximatelyy1000 *B: t. uls per cubiofoot with substantially no attendant formation ';of.-.water gas? ina three-chamber set :which has a:-refractory linedvgenerator having a combustion chamber above :the bottom-20f said:generator,"aqcarburetor chamber and ta superheater zchamber, with w the.

outlet of the combustion chamber communicat-w ing with:.thetinlet :connection of a carburetor containing checkers, and with the; outlet of the carburetor-chamber connecting with the inlet of a superheater containingcheckers, an improved process of "heating which comprises -forming a relatively thin;fan shapedvhorizontal sprayr of. Y fuel oil in ithe.:1ower"portion.ofthe combustion Y chamber but at ailevel substantially above the bottom ofisaid generator, introducing an excess of combustion-:airinto the bottomof said generatorand underneath said oil spray, said air being heating the checkers therein to oil gas making temperaturesrzinxtheneighborhood of 1400 F.

to 1800RFxand'at the same time burning on? any. deposits oficarbonthat'may have been deposited ion .th'ercheckers during the preceding gas making phase:

PAUL L. BORN.

References Citedin the =file of this patent UNITED STATES PATENTS Number Name Date 376,944" Dashiell Jan. 24, 1888 833,182: Smith Oct. 16, 1906 1,053,074- Vuilleumier Feb; 11,1913 1,460,046 Vuilleumier June 26,1923 1,857,469 Miller May 10, 1932 2,131,696 Brandegee Sept. 27, 1938 2,371,616 Hall Mar. 20, 1945' 

1. IN A STANDARD THREE-CHAMBER CARBURETTED WATER GAS SET WHICH HAS A GENERATOR WITH A COMBUSTION CHAMBER AND A CARBURETOR, AND A SUPERHEATER, WITH THE OUTLET OF THE COMBUSTION CHAMBER CONNECTING WITH THE INLET OF THE CARBURETOR CHAMBER AND THE OUTLET OF THE CARBURETOR CHAMBER CONNECTING WITH THE INLET OF THE SUPERHEATER CHAMBER AND WITH SAID LAST TWO CHAMBERS EACH HAVING AN OPERATIVE PORTION OF SAID CHECKERS, AND A GRATE IN THE LOWER PORTION OF SAID GENERATOR BENEATH SAID COMBUSTION CHAMBER AND AIR AND STEAM INLETS IN THE BASE OF THE GENERATOR BENEATH THE GRATE, THE IMPROVEMENT WHICH COMPRISES A COVER OF CHECKERS ON THE GRATE AT THE BOTTOM PORTION OF THE COMBUSTION CHAMBER TO PROTECT THE GRATE, A FUEL OIL SPRAY ADJACENT THE INNER VERTICAL WALL IN THE LOWER PORTION OF THE COMBUSTION CHAMBER ABOVE THE PROTECTIVE CHECKERS ADAPTED TO DISCHARGE A HORIZONTAL SPRAY ACROSS THE LOWER PORTION OF THE COMBUSTION CHAMBER IN PLACE OF USING SOLID FUEL AND THEREBY TO PERMIT AN OPEN COMBUSTION CHAMBER , AND REFRACTORY IGNITION MEANS LOCATED IN SAID COMBUSTION CHAMBER INWARDLY FROM THE WALL AND ABOVE SAID PROTECTIVE CHECKERS IN LINE WITH THE FUEL OIL SPRAY, WHEREBY THE SET MAY PRODUCE GAS HAVING A CALORIFIC VALUE AND SPECIFIC GRAVITY MAKING IT INTERCHANGEABLE WITH NATURAL GAS OF APPROXIMATELY 1000 B. T. U. PER CUBIC FOOT. 